One of the most common ceiling panel systems is a `T` bar ceiling panel system where panels are supported by an exposed `T` bar grid network. There are many manufacturers of `T` bar systems and the individual ceiling panels are received above lower flanges of the `T` bar members which form a frame about the panel. In this type of system, the `T` bar network, and particularly the lower flanges of the T members are visible. A number of systems are available for defining what is referred to as a concealed grid system. In concealed grid systems, the panels typically abut and hide the support grid network. Most of these systems use torsion springs to initially support the panels at a first position spaced significantly below the grid system with the panels being movable to a second position with the panels in engagement with the grid network. The torsion springs maintain the panels in tight engagement with the lower surface of the grid network. Examples of ceiling panel systems are shown in U.S. Pat. No. 4,438,613 and U.S. Pat. No. 4,548,010.
Due to the extreme popularity of `T` bar ceiling systems, installers are intimately familiar with these systems and can quickly install a grid network. Furthermore, there are a huge number of buildings which have such grid networks already in place.